'\" et
.TH STRSIGNAL "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
strsignal
\(em get name of signal
.SH SYNOPSIS
.LP
.nf
#include <string.h>
.P
char *strsignal(int \fIsignum\fP);
.fi
.SH DESCRIPTION
The
\fIstrsignal\fR()
function shall map the signal number in
.IR signum
to an implementation-defined string and shall return a pointer to it.
It shall use the same set of messages as the
\fIpsignal\fR()
function.
.P
The application shall not modify the string returned. The returned
pointer might be invalidated or the string content might be overwritten
by a subsequent call to
\fIstrsignal\fR()
or
\fIsetlocale\fR().
The returned pointer might also be invalidated if the calling thread
is terminated.
.P
The contents of the message strings returned by
\fIstrsignal\fR()
should be determined by the setting of the
.IR LC_MESSAGES
category in the current locale.
.P
The implementation shall behave as if no function defined in this
standard calls
\fIstrsignal\fR().
.P
Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set
.IR errno
to 0, then call
\fIstrsignal\fR(),
then check
.IR errno .
.P
The
\fIstrsignal\fR()
function need not be thread-safe.
.SH "RETURN VALUE"
Upon successful completion,
\fIstrsignal\fR()
shall return a pointer to a string. Otherwise, if
.IR signum
is not a valid signal number, the return value is unspecified.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
If
.IR signum
is not a valid signal number, some implementations return NULL, while
for others the
\fIstrsignal\fR()
function returns a pointer to a string containing an unspecified
message denoting an unknown signal. POSIX.1\(hy2008 leaves this return
value unspecified.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIpsiginfo\fR\^(\|)",
.IR "\fIsetlocale\fR\^(\|)"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<string.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
